I agree that from a single sample you can’t reach conclusions, but “it was their fault” isn’t a great defense.
Many large projects may look like a mess but their success is because they got the high level architecture right and perhaps had the moat of a large tech behemoth behind them.
VSCode, Tensorflow, Kubernetes, Go, Typescript, React. These are a few that come to mind.
At a high level, they are all fantastic projects and perhaps messy in their own way, but they are absolutely fantastic, hardened proven codebases with ~millions of users.
Kubernetes is a complex distributed system with over 2M loc, not matter what the language you use there going to be some issues.
It's probably one of the largest open source project out there.
For example C++ is extremely powerful in writing generic code: Make it a template and and provide a set of of traits to modify the behavior and you get a set of algorithms you can re-use for anything – at the cost of unreadable code in the impelemntation (if you aren't careful; with a chance of quite precise code on the call side) and of course with the bloated version in the resulting binary (after compiler instantiated and inlined (thus copied) everything; where the programmer typically doesn't have to care (till the binary is too large to handle) all of it)
I assumed it is about features because there are really a lot of features inside Kubernetes which are not available in Swarm or Nomad by default.
https://fasterthanli.me/articles/i-want-off-mr-golangs-wild-...
The monotonic time thing is an especially good example.